Polycarbynes are polymers that can be used for the preparation of diamond-like carbon films and in applications that require materials to withstand extreme conditions. Extreme conditions are conditions in which many materials typically fail or lose their structural integrity. Some examples of extreme conditions include extreme temperatures and pressures, high shear or tensile forces, and/or corrosive environments. Presently, metals, high performance plastics, diamonds and other high strength materials are used in many applications in which the materials are exposed to extreme conditions. However, these materials can be cumbersome, expensive and difficult to work with.
For example, diamond is used in and has been proposed for many applications in which materials that can withstand extreme conditions are needed. Diamond is a material from which cutting and drilling tools can be made. Diamond has been proposed for many electronic applications, such as the material from which microelectronic chips are made, because it has high mobility, a high breakdown strength, and a high radiation hardness. However, acquiring natural diamond can be very expensive and/or time consuming because of its scarcity and the difficulty with which it is mined. The difficulty of acquiring natural diamond has led to the need for development of synthetic diamond materials.
Presently, there are several methods for preparing synthetic diamond materials. These methods include use of heat and pressure, chemical vapor deposition, and ultrasonically generated emulsions. Every year tons of commercially manufactured diamond materials are made by heating graphite to about 1370.degree. C. while subjecting it to about 50,000 atmospheres of pressure. This heat and pressure technique converts graphite's layered sheet-like atomic structure to diamond's three-dimensional tetrahedral crystalline network. This technique, however, is cumbersome and requires large and expensive machinery.
Chemical vapor deposition is a cheaper means of manufacturing synthetic diamond. In this process, carbon-containing gas gets decomposed, with microwaves or some other energy source, and the liberated carbon settles on a surface, such as glass or silicon. As the carbon settles, a thin film of solid diamond or diamond-like material develops. However, this film-forming process has not seen wide commercial success because it is very slow and difficult to control.
A recently developed method for preparing diamond-like materials was reported by Glenn T. Visscher et al. in Science, 260, 1496-1498 (1993). This method for preparing diamond-like materials involves transforming a liquid precursor into a synthetic diamond film. In order to achieve the transformation, .alpha.,.alpha.,.alpha.-trichlorotoluene is reduced in tetrahydrofuran, using an ultrasonically generated emulsion of a sodium-potassium alloy, to form poly(phenylcarbyne). The poly(phenylcarbyne) is then pyrolized to form a synthetic diamond material. This process is complex and requires a highly explosive alloy to form the intermediate poly(phenylcarbyne).
Using metal compounds to polymerize organohalides is not new in the art. U.S. Pat. No. 5,211,889 issued on May 18, 1993 to Reuben D. Rieke, specifically discloses examples of soluble highly reactive calcium reacting with dihalothiophenes and dihalobenzenes, for example, to form polymeric materials. However, there is no indication that carbyne-containing organohalides, such as .alpha.,.alpha.,.alpha.-trichlorotoluene, can form polycarbynes using the highly reactive calcium.
A need exists for a facile, relatively safe and inexpensive method of producing polycarbynes with reasonably high yields. This facile method should be readily adaptable to the production of a variety of polycarbyne materials. Once produced, polycarbynes can be converted into a synthetic diamond material, a plastic material, or other high strength material that maintains its structure in extreme conditions.